System and method for selecting wireless signal bandwidth based on signal strength measurements provided by wireless receivers

ABSTRACT

A method and system are provided which combine (i) adaptive multi-rate half-rate transmission and (ii) intelligent frequency hopping wherein frequency hopping and intelligent underlay overlay are used simultaneously. In the latter, frequency hopping is controlled on a frequency group by frequency group basis, and one frequency hopping group is made up of one or more regular transmitters of a cell and another frequency hopping group is made up of one or more super reuse (super layer) transmitters of the cell. A wireless terminal (e.g., handset) is used in determining the carrier to interference (C/I) ratio for a received signal. A determination is then made as to whether the C/I ratio is acceptable for super layer transmission, and, if the ratio is acceptable, a super reuse transmitter operating in the superlayer range at the half-rate transmission rate is used to transmit a call to the terminal.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/152,370, filed on Jun. 15, 2005, entitled “SYSTEM AND METHOD FORSELECTING WIRELESS SIGNAL BANDWIDTH BASED ON SIGNAL STRENGTHMEASUREMENTS PROVIDED BY WIRELESS RECEIVERS”, which claims benefit ofU.S. Provisional Patent Application Ser. No. 60/615,575, filed on Oct.5, 2004, the entireties of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of determining transmissionsignal bandwidth for wireless network communications.

2. Description of the Related Art

Wireless frequency availability and signal bandwidth are critical tomaximization of wireless telecommunications capabilities. A wirelessnetwork has a limited bandwidth and number of frequencies available forwireless telecommunications. As demand for wireless network services hasincreased, it has become necessary to provide as much bandwidth and themaximum number of frequencies in each wireless network cell and sector.

The present state of the art in wireless communications provides varioustechniques for maximizing bandwidth and frequency use. Generally,however, these techniques are dependent upon the strength andcharacteristics of the signal as received by the wireless device. If thesignals are not strong and clear, then a broader bandwidth or adifferent frequency may be required in order to assure reliablecommunications with the wireless device and avoid interference.

As discussed below, embodiments of the present invention are based, inpart, on a combination of two existing technologies. These technologiesare discussed below.

SUMMARY OF THE INVENTION

In accordance with embodiments of the invention, a method and system areprovided which combine the hardware and cost efficiency of AdaptiveMulti-Rate (AMR) Half-Rate (HR) with the spectrum efficiency andpredictability of Intelligent Frequency Hopping (IFH), two technologiesthat are described in more detail hereinafter. In one importantimplementation, efficient half-rate transmissions are applied to thesuper layer, and such application is based on, and protected by, thecarrier to interference (C/I) ratio prediction and layer determinationmechanisms of IFH. In this implementation, full-rate transmissions areapplied to the regular layer, and are used to serve areas where the IFHmechanism determines that radio conditions (e.g., the C/I ratio) areinadequate for AMR half-rate. (It is noted that the terms super, superreuse, super layer and underlay are often used interchangeably, as areregular layer and overlay; the terms super layer and regular layer areused herein and are discussed in more detail below.) As with IFH, inthis implementation of the invention, the transmitter resources aredivided the super and regular layers but the super layer half-ratetransmitters are able to serve twice as many calls. In such animplementation, the doubling of super layer transmission capacityoffsets the trunking efficiency loss of layer subdivision, andsignificantly improves overall hardware efficiency. It is noted thatsuper layer and regular layer transmissions use the same number ofhopping frequencies and because scarce frequency resources are notsubdivided between layers, spectrum efficiency is optimized with thisimplementation.

An important feature of this implementation is that calls are applied tohalf-rate under all loading conditions and not just during peak-usageperiods. The method and system of this implementation (i) check radioconditions (and, in a preferred embodiment, check the C/I ratio), beforeapplying calls to half-rate, whereas conventional packing does not, and(ii) proactively places calls on half-rate whenever these conditions aremet, whereas conventional packing waits until the available resourcesare near congestion.

In general, as is described in more detail below, the method and systemof preferred embodiments of the invention, among other advantages,provide a more consistent half-rate call quality, proactively reduceinterference, thereby improving overall capacity and performance, anddeliver higher half-rate absorption and cost savings.

In accordance with one aspect of the invention, there is provided amethod for selecting a wireless signal bandwidth for wirelesscommunication with a wireless terminal in a system comprising aplurality of cells each including at least one regular layer frequencyhopping transmitter and at least one super layer transmitter frequencyhopping transmitter, and wherein at least first and second transmissionrates are available, the second transmission rate serving more callsusing a single transmitter than the first transmission rate for the sametransmitter, the method comprising the steps of:

measuring signal strength of a received signal using the wirelessterminal and producing a relative signal strength measurement based atleast in part thereon;

determining whether said relative signal strength measurement is withina predetermined threshold consistent with super layer operation; and

if the relative signal strength measurement is not within saidthreshold, providing transmission to the wireless terminal at the firsttransmission rate using the at least regular layer transmitter, and ifthe relative signal strength measurement is within said threshold,providing transmission to the wireless terminal at a second transmissionrate using the at least one super layer transmitter.

Preferably, the first and second transmission rates comprise full-ratetransmission and half-rate transmission.

The step of measuring relative signal strength preferably comprisesdetermining a carrier to interference ratio for the received signal.

Advantageously, at least two super layer transmitters are provided ateach cell.

Preferably, the measuring step is carried out continuously, and, if acurrent relative signal strength measurement is not within thepredetermined threshold after formerly being within the predeterminedthreshold, transmission is switched to transmission at the firsttransmission rate using the at least one regular layer transmitter.

According to a further aspect of the invention, there is provided amethod combining (i) adaptive multi-rate half-rate transmission and (ii)intelligent frequency hopping wherein frequency hopping and intelligentunderlay overlay are used simultaneously, wherein, in a base controller,frequency hopping is controlled on a frequency group by frequency groupbasis, and wherein a frequency hopping group comprises at least oneregular transmitter of a cell and another frequency hopping groupcomprises at least one super reuse transmitter of the cell, the methodcomprising the steps of:

using a wireless terminal in determining a carrier to interference ratiofor a signal received thereby;

determining whether the ratio is acceptable for super layertransmission; and

if the ratio is acceptable, using the at least one super reusetransmitter to transmit in a superlayer range at the adaptive multi-ratehalf-rate transmission rate and if the ratio is not acceptable, usingthe at least one regular transmitter to transmit in a regular layerrange at a full rate transmission rate.

Preferably, the determining step comprises determining whether thecarrier to interference ratio is within a predetermined threshold.

Preferably, the measuring step is carried out continuously, and, if acurrently determined carrier to interference ratio is not within thepredetermined threshold after formerly being within the predeterminedthreshold, transmission is switched to transmission at the firsttransmission rate using the at least one regular transmitter.

In accordance with another aspect of the invention, there is provided amethod for controlling call placement to a wireless terminal in a systemthat comprises a plurality of cells each including at least one regularlayer frequency hopping transmitter and at least one super layerfrequency hopping transmitter and wherein adaptive multi-rate half-ratetransmission is available, the method comprising the steps of:

using the wireless terminal in providing a carrier to interference ratiomeasurement with respect to a signal received by the wireless terminal;

determining whether the carrier to interference measurement meetspredetermined conditions indicating acceptability for super layertransmission; and

if said predetermined conditions are met, using the at least one superlayer transmitter to place a call to the wireless terminal usingadaptive multi-rate half-rate transmission.

Preferably, the determining step comprises determining whether thecarrier to interference ratio is within a predetermined threshold.

Preferably, carrier to interference ratio measured is carried out on acontinuous basis, and, if a current measurement is not within thepredetermined threshold after formerly being within the predeterminedthreshold, the call is switched to transmission at a full-ratetransmission rate using the at least one regular layer transmitter.

According to yet another aspect of the invention, there is provided awireless communication system comprising:

a plurality of cells each including at least one regular layer frequencyhopping transmitter and at least one super layer frequency hoppingtransmitter, and

at least one wireless terminal for measuring relative signal strength ofa received signal;

said cells each further comprising a cell tower for receiving incomingcalls and a controller for controlling switching between the at leastone regular layer transmitter and the at least one super layertransmitter based on whether the measured relative signal strength ofthe received signal meets at least one predetermined condition relatingto acceptability for super layer transmission, and for, when said atleast one condition is met, providing for switching to the at least onesuper layer transmitter and for transmission of a call to the wirelessterminal from the at least one super layer transmitter at an adaptivemulti-layer half-rate.

Advantageously, the system comprises at least two super layer frequencyhopping terminals.

Preferably, the controller controls said switching based on whether themeasured relative signal strength exceeds a predetermined threshold.

Preferably, a carrier to interference ratio is determined for thereceived signal and the controller controls switching betweentransmitters based on whether the ratio exceeds a predeterminedthreshold.

Preferably, the wireless terminal continuously measures relative signalstrength, and, if a current relative signal strength measurement nolonger exceeds the predetermined threshold after formerly exceeding saidthreshold, the controller provides for switching to transmission of thecall at a full-rate transmission rate using the at least one regularlayer transmitter.

According to still another aspect of the invention, there is provided acomputer-readable medium having computer executable instructions storedthereon for performing a method for controlling call placement to awireless terminal in a system that comprises a plurality of cells eachincluding at least one regular layer frequency hopping transmitter andat least one super layer frequency hopping transmitter and whereinadaptive multi-rate half-rate transmission is available, the methodcomprising the steps of:

receiving an input comprising a carrier to interference ratio based onrelative signal strength measurements made by the wireless terminal;

determining whether the carrier to interference ratio meetspredetermined condition indicating acceptability for super layertransmission; and if the predetermined conditions are met, providing foruse of the at least one super layer transmitter to place a call to thewireless terminal using adaptive multi-rate half-rate transmission.

Preferably, the predetermined conditions include whether the ratioexceeds a predetermined threshold, and if the ratio no longer exceedsthe predetermined threshold, providing switching to transmission of thecall using the at least one regular layer transmitter transmitting at afull-rate transmission rate.

Further features and advantages of the present invention will be setforth in, or apparent from, the detailed description of preferredembodiments thereof which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a wireless network used in explanationof one aspect of the present invention.

FIG. 2 is a flowchart of an exemplary embodiment of one aspect of thepresent invention.

FIG. 3 is a flowchart of an exemplary embodiment of another aspect ofthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments of the present invention will now be described indetail by reference to the drawings. In referring to the drawings, thenumbered components described herein refer to like numbered componentsdepicted in the drawings.

Referring to FIG. 1, a wireless cellular network 100 is shown. In anexemplary embodiment of the system and method of the present invention,the network 100 provides a combination or selection of transmissionsystems and methods appropriate for the specific wireless communicationlinks based on the measurement of relative signal strength and inparticular, carrier to interference ratio. As indicated above, thesesystems and methods include, but are not limited to, intelligentfrequency hopping (IFH) and adaptive multi-rate (AMR) half rate (HR).These methods are combined in the manner described herein, to form whatis referred to herein, for shorthand purposes, as an Intelligent PackingHalf rate (IPH) system. As mentioned above and is described below, thissystem delivers superior service quality, and superior hardware andspectrum efficiency. Before considering FIG. 1 in more detail, IFH willfirst be described.

Considering IFH in more detail, IFH is a system (and associated method)which is designed to improve spectrum efficiency and capacity. Thesystem is referred to as intelligent frequency hopping because frequencyhopping (FH) and intelligent underlay overlay (IUO) are usedsimultaneously to improve the capacity of the radio network. When theIUO feature is deployed in the base station controller, frequencyhopping is controlled on a frequency group by frequency group basis.Regular transmitters of the cell compose one hopping group and superreuse transmitters of the cell compose another hopping group. Frequencyhopping can be used independently in these two groups. The following isa brief description of the two techniques that comprise IFH, viz.,frequency hopping and IUO.

Frequency hopping can briefly be described as a sequential change ofcarrier frequency on the radio link between the mobile terminal and thebase station. When frequency hopping is used in TDMA, for example, thecarrier frequency is changed between each consecutive TDMA frame. Thismeans that, for each connection, the change of the frequency may happenbetween every burst. Frequency hopping also provides some additionalbenefits such as frequency and interference diversity.

Intelligent underlay-overlay (IUO) is designed to allow the operator toreuse frequencies very aggressively in order to achieve higher radionetwork capacity. To avoid interference caused by aggressive frequencyreuse, the base station controller (BSC) estimates the degree ofinterference on different frequencies and directs the mobile stations tothose frequencies that are clean enough to sustain a good radioconnection quality.

Turning again to FIG. 1, wireless cellular network 100 includes wirelessterminals, i.e., receivers or handsets, 110 a, 110 b and 110 c. It will,of course, be understood that the number of receivers or handsets can bemuch greater than the three shown. Three cell towers or cell sites 112a, 112 b and 112 c are also shown. Again, it will be appreciated thatthe number shown is arbitrary. The wireless receivers 110 a, 110 b and110 c are shown as being cellular phones. However, it will be understoodby one skilled in the art that wireless receivers could also be otherforms of wireless communications devices including, but not limited to,wireless pagers or computers (including PDAs and laptop computers).

As indicated above, FIG. 1 is presented as an aid to understand certainaspects of the invention. In this regard, super layers 114 are shownwhich surround the respective cell sites 112 a, 112 b and 112 c, whileregular layers 116 are also shown which surround the respective superlayers 114. The super layers 114 serve the inner regions of the cellsites 112 a, 112 b and 112 c of network 100 where there is little or nointerference with the signal transmission that occurs between a wirelessreceiver and a corresponding transmitter.

As mentioned above and is explained below, in accordance with one aspectof the invention, signal transmissions occurring within a super layer114 are transmitted at half rate, but transmission can take place in therespective super layer 114 only if the corresponding carrier tointerference (C/I) ratio for the signal is within a given range and,more particularly, above a predetermined level. Due to the nature of asuper layer 114, an area serviced by the layer will have clear dominanceover an area serviced by the associated regular layer 116 whichtransmits at full rate. As indicated above, benefits of the half ratetransmission include less overall transmission interference and lessequipment.

A regular layer 116 serves the cell border and areas with highinterference. As a result half rate transmission is not used here. Theregular layer is used primarily to provide coverage. Therefore, thetransmitters must be more robust to handle transmissions characterizedby low carrier to interference ratios.

A plurality of transmitters is associated with each of the cell sites,with three transmitters 109 a, 109 b and 109 c being shown in FIG. 1 asbeing associated with cell site 112 c. As explained below, at least twoand preferably three hopping transmitters are employed per sector and,in a preferred embodiment, at least two transmitters in the sectorassociated with cell site 112 c, e.g., transmitters 109 a and 109 b arecapable of operating at half-rate to address the super layer 114 and atleast one further transmitter, e.g., transmitter 109 c, is capable ofoperating at full-rate to address the regular layer 116. A controller111 of cell site 112 c controls switching between transmitters 109 a,109 b and 109 c, among other functions.

It will, of course, be understood that the shapes of layers 114 and 116shown in FIG. 1 are highly schematic and would not normally be that ofan ordinary circle.

With this background, returning to a consideration of IFH, as previouslystated, IFH, in brief, combines simultaneously operating FH and IUO. Todo so, IFH uses the GSM signal strength measurements received from thewireless receivers (e.g., corresponding to handsets 110 a, 110 b, and110 c of FIG. 1) to determine radio conditions, i.e., to determine thecarrier to interference (C/I) ratio. These C/I ratio determinations aretypically used to decide from which cell site (e.g., from which one ofcell sites 112 a, 112 b or 112 c of FIG. 1) the call is to be serviced.Additionally, in typical network operations, the call can either beserviced by the regular layer (e.g., layer 116 in FIG. 1), which ischaracterized by conservative loading and low efficiency transmitters(e.g., transmitter 109 c of FIG. 1), or the super layer (e.g., layer 114in FIG. 1), which is characterized by aggressive loading and highefficiency transmitters (e.g., transmitters 109 a and 109 b of FIG. 1).

For traditional IFH applications, a regular layer transmitter usesreduced frequencies that are infrequently reused in nearby sectors. Asdiscussed above, regular layer transmissions therefore enjoy favorableradio conditions for the served area but are inefficient. On the otherhand, a super layer transmitter uses high interference frequencies thatare frequently reused in nearby sectors. These transmitters normally areeffective for a smaller subset of the served area, but are moreefficient and provide greater capacity. Therefore, IFH traditionallyapplies most of the calls to the super layer whenever the C/I ratio isadequate, with regular layer transmitters being used only where the C/Iratios are deemed inadequate for the super layer.

Considering in more detail AMR half rate, which is the other techniqueor technology used by the IPH system and method of the invention, thisterm refers to a standard GSM system and method which allows a serviceprovider to, for example, serve 16 calls on a transmitter that normallyserves 8 AMR full rate calls. Fewer half rate radios (transceivers) aretherefore required to service a given amount of subscriber traffic. Itwill be understood that each transmitter creates interference andtherefore, fewer transmitters means less interference and greatercapacity. However, AMR half rate call quality is similar to AMR fullrate if applied under appropriate conditions. More specifically, AMRhalf-rate calls require more favorable radio conditions than AMR fullrate, and radio conditions in frequency hopping GSM networks deteriorateas subscriber traffic and interference reach their peak. Therefore,conventional systems tend to pack (migrate full rate to half rate) callsduring peak loading periods when radios are near congestion. The marginoccurs when radio conditions are least favorable to AMR half rate.Conventional systems are also unable to accurately predict radioconditions before packing and thus, half rate call quality isunpredictable. Therefore, AMR half rate is currently underutilized as aresult of this inability to control the radio conditions and resultingcall quality.

Turning again to the IPH method and system of the invention, in order toovercome the problems associated with the separate use of IFH and AMRhalf rate, Intelligent Packing for Half rate (IPH) combines the hardwareand cost efficiency of AMR half rate with the spectrum efficiency andpredictability of IFH. As indicated above, efficient half ratetransmission are applied to the super layer and reliability is enhancedby using the C/I prediction and layer determinations of IFH. Full ratetransmissions are applied to the regular layer and used to serve areaswhere IFH has determined radio conditions, based on C/I attenuations, tobe inadequate for AMR half rate. As with IFH, transmitter resources aresubdivided between super and regular layers, yet super layer half ratetransmitters serve twice as many calls. As discussed above, thisdoubling of super layer transmitter capacity offsets the trunkingefficiency loss of layer subdivision and improves hardware efficiency bya significant margin. The super and regular layer transmitters use thesame pool of frequencies. As a consequence, scarce frequency resourcesare not subdivided between layers, therefore spectrum efficiency isoptimized. As mentioned previously, the IPH method applies calls to halfrate under all loading conditions, not just during peak usage periods.Therefore, the IPH method is an effective and proactive techniques whichimproves hardware usage, reduces cost, enhances spectrum efficiency andimproves performance.

Considering the operation of the IPH system and method in more detail,FIG. 2 illustrates the steps involved in one preferred embodiment of theoperation. In a first step, indicated by block 210, carrier tointerference (C/I) ratio values are determined based on signal strengthmeasurements made by the associated handsets. Next, as indicated bydecision diamond 212, a determination is made as to whether the C/Iratio is within the range required by, i.e., is compatible with, superlayer operation. If the carrier to interference ratio is within thisrange, i.e., the decision is “yes,” operation will then be switched orhanded off from the regular layer to the super layer (assuming initialregular layer transmission) and half rate transmission will begin, asshown by block 216. However, if the carrier to interference ratio is notwithin the super layer range, i.e., the decision is “no,” then thetransmission will continue to full rate. Full rate transmission willthus continue until the C/I ratio determined is within the range neededfor super layer operation.

Once operation has switched to super layer operation using a super layertransmitter operating in half rate transmission mode, there is acontinuous monitoring of the carrier to interference ratio, asillustrated by decision diamond 218. If the carrier to interferenceratio remains within the predetermined super layer range, i.e., thedecision is “yes,” the transmission will continue to occur in the superlayer at half rate. However, if the carrier to interference ratio dropsbelow the predetermined range, i.e., the decision is “no,” the operationwill switch back to the regular layer and full mode transmission, asshown by block 220. The continuous monitoring of the carrier tointerference ratio continues throughout the operation as is shown by thearrow leaving block 220 and returning to the input of decision diamond212.

Referring to FIG. 3, there is shown an illustrative sequence of an IPHimplementation in accordance with an exemplary embodiment. In order toget maximum advantage from IPH, suitable transmission sectors have to beselected, and three initial tests are preferably carried out todetermine whether the IPH system should be implemented in a particularsector. As shown in FIG. 3, the first step in the implementation processis making certain that the system has sufficient equipment, asillustrated by block 310. As indicated above, there is a requirement forat least two (and preferably three) hopping transmitters per sector. Atleast one of the transmitters in the sector will be capable of operatingin full rate to address the regular layer and the other transmitter (ortransmitters) in the sector will be capable of operating at half rate toaddress the super layer. It is noted that the sector will be unable toaccept traffic on either layer if the regular layer is full, regardlessof the number of idle super layer timeslots.

Next, the codec distribution must be checked to ensure that the signalis of sufficient quality for the layer in the transmission will beoccurring, as shown by block 312. If the codec distribution is high,transmission at half rate is easier to achieve. More specifically,serving more than 70% of the samples on full rate codec, 12.2, makes iteasier to achieve half rate using the super layer. If the codecdistribution is low, then super layer transmission will not be the bestmethod to use to transmit the signal. The codec distribution ispreferably used to estimate the C/I ratio in the service area.

Once the codec distribution has been checked, the next step is to checkthe downlink receiver (DL Rx) level distribution of the broadcastcontrol channel (BCCH) transmission to determine the direct access level(DAL) threshold, as illustrated by block 314. There should be asufficient number of samples on the BCCH in order to provide a goodindication of the DL Rx level without power. A significant number ofsamples above −85 dBm provides assurance that the mobile station will beable to keep the half rate call in good C/I conditions for quite sometime. This test assures the user that the relative signal strength(e.g., C/I ratio) is adequate to be used by the IPH system for superlayer half rate calls.

Once it has been determined that there is sufficient equipment andsignal quality, along with adequate relative signal strength (e.g., C/Iratio) to support the super layer, a drive test is preferably performed,in scan mode, using default parameters, as shown by block 316. Drivetests can be processed to estimate the carrier to interference ratiothresholds for the super and regular layers.

Considering the drive test requirement in more detail, a thorough drivetest is preferably used to monitor the performance of the test cluster.In addition to statistical data, drive tests provide information whichcan be further scrutinized for the purpose of identifying anomaliesoccurring in the network. This information can also be used to validatefindings resulting from statistical and field analysis.

In preparing a drive test, a detailed drive route of the cluster ismapped. The route should ensure coverage of all sectors within thecluster. The route should also cross the boundary in several places ofthe test cluster. This is necessary to monitor handovers occurringbetween sites in and out of the test area. A baseline drive should beundertaken before any changes are implemented. This will provide afoundation on which to base the progression of the cluster. For anaccurate analysis, all post change drive tests should be performed closeto, or at the same time of day at which the baseline test was done. Ingeneral, the best time to conduct a drive test is during the busy hourof the test cluster. This will provide knowledge of the worst userperceived performance in the area.

Once good IPH candidate sectors are identified, implementation can takeplace. Referring again to FIG. 3, the next step is to lock the sectorand transmitter in order to change the mobile allocation index offset(MAIO) and time slot (TSL) from full to half rate, as shown by block320. This step is considered in more detail below, in connection withFIG. 4.

It should also be noted that for successful functioning of IPH, a properreference cell list should be defined, as shown by block 322. The celllist is used to calculate or estimate the C/I of the cell. This isimportant in deciding the absorption on the super layer and the userperceived voice quality. Neighbors of the sector can only be a part ofthe reference cell list. There are two important factors in generatingthe reference cell list, viz., traffic distribution in the cell andoverlapping of neighbors. Both can be very closely related to handoverbetween adjacent cells

To determine the neighbor pairs that are candidates for the referencecell list, the total number of hand over on every adjacent/neighborsector should be determined and their cumulative percentages should becalculated. Once the cumulative percentages have been calculated theneighbors with a cumulative percentage of at least 95% are consideredcandidates for the reference cell list.

Lastly, to confirm correct implementation a post drive test isperformed, as illustrated by block 324.

Care should be taken during the step 320 because one mistake could causesignificant degradation to system performance. Therefore, in accordancewith a further aspect of the invention, certain precautions should betaken. For example, the underlay MAIO step and MAIO offset should beplanned as an independent sector. Further, a separate MAIO plan for theTRX of this layer should be included. In addition, the existence of fulland half rate calls should be verified after implementation on a sector.Also, a conventional averaging method should be used for IUO. Further,the last TRX in the BTS should be used as the super TRX. In addition, ifan interferer is suspected to be missing, the channel finder reportshould be run to find those cells. Once those cells are found theyshould be defined as neighbors and added in the TRX reference cell list.

Considering underlay MAIO planning in more detail, correct underlay MAIOplanning is the key to a successful IPH implementation. Referring toFIG. 4, the illustrated process is preferably used to define underlayMAIO (offset) using MAIO step and MAIO (offset). For proper MAIOplanning, the MAIO step in the super layer and regular layer should bethe same, as shown by block 400. Next, care should be taken to ensurethat the underlay MAIO step equals the MAIO step, as shown by block 410.To assist in step 410, it is helpful if the matrix of the underlay MAIOoffset is plotted, as indicated by block 412. An example of such a plotis shown in FIG. 5, for a “Sector A.” As indicated, MAIO is not for thefirst BCCH transmitter (TRX1) and is only for the hopping transmitters(TRX2, TRX3 and TRX4). As is also indicated, MAIO for every transmitteris calculated from the MAIO offset and the MAIO step. MAIO for the firsthopping transmitter (TRX2) corresponds to the MAIO offset of the sector(sector A). MAIO for the second hopping transmitter (TRX3) in the samesector with the MAIO offset added to the MAIO step (0+3=3) and,similarly, MAIO for any additional transmitter is incremented by theMAIO step (which in the example is 3) so that, in the example, for thirdhopping transmitter (TRX4) MAIO is 6 (3+3=6). For the ease of underlayMAIO planning, the last transmitter (TRX4) should be converted to asuper transmitter, as shown by block 414, and any additional supertransmitter (TRX) should be populated together.

Although the invention has been described above in relation to preferredembodiments thereof, it will be understood by those skilled in the artthat variations and modifications can be effected in these preferredembodiments without departing from the scope and spirit of the invention

1. A method, comprising: if a number of frequency hopping transmitters,an amount of codec distribution, and a direct access level in atransmission sector are within a first predetermined threshold, a secondpredetermined threshold and a third predetermined threshold,respectively, drive testing the transmission sector in scan mode basedon at least one default parameter to determine at least one estimatedcarrier to interference ratio threshold for at least one super layerfrequency hopping transmitter and at least one regular layer frequencyhopping transmitter; and locking the transmission sector and changing amobile index offset (MAIO) and a time slot (TSL) from full rate to halfrate for the at least one super layer frequency hopping transmitter. 2.The method of claim 1, further comprising: measuring the number offrequency hopping transmitters in the transmission sector; anddetermining whether the number of frequency hopping transmitters in thetransmission sector is within the first predetermined threshold.
 3. Themethod of claim 1, further comprising: measuring the amount of codecdistribution in the transmission sector; and determining whether theamount of codec distribution in the transmission sector is within thesecond predetermined threshold.
 4. The method of claim 1, furthercomprising: measuring a downlink receiver (DL Rx) level distribution ofa broadcast control channel (BCCH) of the transmission sector todetermine the direct access level; and determining whether the directaccess level is within the third predetermined threshold consistent witha signal strength for super layer half rate calls.
 5. A method accordingto claim 1, wherein the drive testing includes at least one of mapping adetailed drive route of the transmission sector or conducting a baselinedrive of the transmission sector.
 6. A method according to claim 1,further comprising defining a reference cell list.
 7. A method accordingto claim 6, wherein the defining includes defining the reference celllist based on at least one of traffic distribution in the transmissionsector or an amount of overlap of neighboring transmission sectors tothe transmission sector.
 8. A method according to claim 1, furthercomprising unlocking the transmission sector and performing a seconddrive test of the transmission sector.
 9. A method according to claim 8,wherein the second drive test includes at least one of mapping adetailed drive route of the transmission sector or conducting a baselinedrive of the transmission sector.
 10. A method according to claim 8,further comprising determining whether the second drive test meets afourth predetermined threshold for implementation of an intelligentpacking half-rate (IPH) system.
 11. A system comprising: a receivercomponent configured to receive a number of frequency hoppingtransmitters, an amount of codec distribution, and a direct access levelin a transmission sector; a testing component configured to perform adrive test in scan mode based on at least one default parameter todetermine at least one estimated carrier to interference ratio thresholdfor at least one super layer frequency hopping transmitter and at leastone regular layer frequency hopping transmitter; and an update componentconfigured to lock the transmission sector and change a mobile indexoffset (MAIO) and a time slot (TSL) from full rate to half rate for theat least one super layer frequency hopping transmitter.
 12. A systemaccording to claim 11, wherein the receiver component determines whetherthe number of frequency hopping transmitters in the transmission sectoris within a first predetermined threshold.
 13. A system according toclaim 11, wherein the receiver component determines whether the amountof codec distribution in the transmission sector is within a secondpredetermined threshold.
 14. A system according to claim 11, wherein thereceiver component measures a downlink receiver (DL Rx) leveldistribution of a broadcast control channel (BCCH) of the transmissionsector to determine the direct access level; and determines whether thedirect access level is within a third predetermined threshold consistentwith a signal strength for super layer half rate calls.
 15. A systemaccording to claim 11, wherein the testing component performs a drivetest that at least one of maps a detailed drive route of thetransmission sector or conducts a baseline drive of the transmissionsector.
 16. A system according to claim 11, wherein the update componentfurther defines a reference cell list.
 17. A system according to claim16, wherein the update component defines the reference cell list basedon at least one of traffic distribution in the transmission sector or anamount of overlap of neighboring transmission sectors to thetransmission sector.
 18. A system according to claim 11, furthercomprising a diagnostic component configured to unlock the transmissionsector and perform a second drive test of the transmission sector thatat least one of maps a detailed drive route of the transmission sectoror conducts a baseline drive of the transmission sector.
 19. A systemaccording to claim 18, wherein the diagnostic component furtherdetermines whether the second drive test meets a fourth predeterminedthreshold for implementation of an intelligent packing half-rate (IPH)system.
 20. A computer implemented system, comprising: means fordetermining if a number of frequency hopping transmitters is within afirst predetermined threshold; means for determining if an amount ofcodec distribution is within a second predetermined threshold; means fordetermining if a direct access level in a transmission sector is withina third predetermined threshold; means for drive testing thetransmission sector in a scan mode based on at least one defaultparameter to determine at least one estimated carrier to interferenceratio threshold for at least one super layer frequency hoppingtransmitter and at least one regular layer frequency hoppingtransmitter; and means for locking the transmission sector and changinga mobile index offset (MAIO) and a time slot (TSL) from full rate tohalf rate for the at least one super layer frequency hoppingtransmitter.